Update changelog for v1.1.0
Update changelog for v1.1.0

nickjj/build-a-saas-app-with-flask,z123/build-a-saas-app-with-flask,nickjj/build-a-saas-app-with-flask,nickjj/build-a-saas-app-with-flask,nickjj/build-a-saas-app-with-flask,z123/build-a-saas-app-with-flask,z123/build-a-saas-app-with-flask